byGramling, Cheryl; Carpenter, Russell; Lee, Taesul; Long, Ann
This paper evaluates several navigation approaches for the Magnetospheric Multiscale (MMS) mission, which consists of a tetrahedral formation of satellites flying in highly eccentric Earth orbits. For this investigation, inter-satellite separations of approximately 10 kilometers near apogee are used for the first two phases of the MMS mission. Navigation approaches were studied using ground station two-way Doppler measurements, Global Positioning System (GPS) pseudorange measurements, and... Topics: SPACE PROBES, SATELLITE ATMOSPHERES, INTERPLANETARY TRAJECTORIES, ACCELERATION (PHYSICS), SOLAR...
We show that quantum effects are likely to significantly degrade the performance of MOSFETs (metal oxide semiconductor field effect transistor) as these devices are scaled below 100 nm channel length and 2 nm oxide thickness over the next decade. A general and computationally efficient electronic device model including quantum effects would allow us to monitor and mitigate these effects. Full quantum models are too expensive in multi-dimensions. Using a general but efficient PDE solver called... Topics: HOLOGRAPHY, LAUNCHING, SOLAR SAILS, PERIHELIONS, SUMMER, TRAJECTORIES
Digital image processing techniques were used to develop algorithms for automatic detection of human motion trajectories in this study. Based on these algorithms, the marker-free analysis system has been developed and tested in analysis of human gait. Experiments have been made on a group of ten healthy male subjects whose walking was captured by standard camera. Here, only the movements of lower limbs’ anatomical landmarks in sagittal plane were considered. Trajectories of hip,... Topics: Motion Trajectories, Gait Analysis, Anatomical Joint Angles
A propulsor blade for an aircraft engine includes an airfoil section formed in the shape of a scimitar. A metallic blade spar is interposed between opposed surfaces of the blade and is bonded to the surfaces to establish structural integrity of the blade. The metallic blade spar includes a root end allowing attachment of the blade to the engine. Topics: BALLISTIC TRAJECTORIES, ELECTRODES, ELECTRON TUNNELING, PATENTS
Direct current analog computer for calculating trajectory of missile on reentry from data recorded in flight Topics: ANALOG COMPUTERS, DATA RECORDING, DIRECT CURRENT /DC/, MISSILE TRAJECTORY, REENTRY TRAJECTORY, DATA...
Presented at Conference in Computing Methods in Optimization Problems at University of California, Los Angeles, California, January 1964 Topics: Space trajectories., Ballistics, Exterior--Tables., Programming (Mathematics), Calculus of... Source: half
byRobertson, Franklin R.; Fitzjarrald, Dan E.; Kummerow, Christian D
Considerable uncertainty surrounds the issue of whether precipitation over the tropical oceans (30 deg N/S) systematically changes with interannual sea-surface temperature (SST) anomalies that accompany El Nino (warm) and La Nina (cold) events. Time series of rainfall estimates from the Tropical Rainfall Measuring Mission (TRMM Precipitation Radar (PR) over the tropical oceans show marked differences with estimates from two TRMM Microwave Imager (TMI) passive microwave algorithms. We show that... Topics: SPACE SHUTTLE BOOSTERS, ABORT TRAJECTORIES, SEGMENTS, SPACE SHUTTLES, CONFERENCES
AN INVESTIGATION WAS MADE OF MISLEADING RESULTS OF TEST FOR CYTOMEGALOVIRUS INFECTION. IT WAS FOUND THAT THESE INFECTIONS MAY BE CONDITIONED BY PREVIOUS OCCURRENCE OF DISSEMINATED LUPUS ERYTHEMATOSUS. Topics: ASTRONAUTICS, HISTORIES, POLAND, ROCKET VEHICLES, ROCKET LAUNCHING, SPACECRAFT TRAJECTORIES
Wind-tunnel tests of a 1/5-scale semispan model of the Republic XF-12 horizontal tail surface equipped with an internally balanced elevator were conducted in the 6- by 6-foot test section of the Langley stability tunnel. The tests included measurements of the aerodynamic characteristics of the horizontal tail with and without a beveled trailing edge and also included measurements of the tab characteristics. The variation of the aerodynamic characteristics with boundary-layer conditions and... Topics: AIRSPACE, DISPLAY DEVICES, REACTION TIME, CUES, FLIGHT CREWS, TRAJECTORIES, JUDGMENTS
The results are presented of a project of research and development on strategies for optimizing the instructional process, and dissemination of information about the applications of such research to the instructional medium of computer-assisted instruction. Accomplishments reported include construction of the author language INSTRUCT, construction of a practical CAI course in the area of computer science, and a number of investigations into the individualization of instruction, using the course... Topics: ABORT TRAJECTORIES, LAUNCHING, SPACE SHUTTLES, ENGINE CONTROL, OPTIMIZATION
byCoy, E. B.; Greenfield, S. C.; Ondas, M. S.; Song, Y.-H.; Spegar, T. D.; Santavicca, D. A
The goal of this research is to experimentally characterize the behavior of droplets in vaporizing liquid sprays under conditions typical of those encountered in high pressure combustion systems such as liquid fueled rocket engines. Of particular interest are measurements of droplet drag, droplet heating, droplet vaporization, droplet distortion, and secondary droplet breakup, under both subcritical and supercritical conditions. The paper presents a brief description of the specific... Topics: COST EFFECTIVENESS, RENDEZVOUS TRAJECTORIES, ROBOT SENSORS, SPACE RENDEZVOUS, SPACECRAFT CONTROL,...
AN EXPERIMENTAL PROGRAM IN WHICH SALT-SPRAY-EXPOSED COATINGS HAVE BEEN IRRADIATED IS DESCRIBED AND DISCUSSED. Topics: APOLLO 15 FLIGHT, SPACE NAVIGATION, SPACECRAFT CONTROL, SPACECRAFT GUIDANCE, SYSTEMS ANALYSIS,...
A series of fatigue tests with specimens subjected to constant amplitude and two-step axial loads were conducted on 12-inch-wide sheet specimens of 2024-T3 and 7075-T6 aluminum alloy to study the effects of a change in stress level on fatigue-crack propagation. Comparison of the results of the tests in which the specimens were tested at first a high and then a low stress level with those of the constant-stress- amplitude tests indicated that crack propagation was generally delayed after the... Topics: INERTIAL GUIDANCE, REENTRY VEHICLES, REENTRY GUIDANCE, SATELLITE GUIDANCE, REENTRY, DESCENT...
The Southern Durchmusterung (SD, Schoenfeld 1886, Becker 1949, Schmidt 1967) is a visual survey of stars in the declination zones -02 to -23 deg, completed as an extension to Argelander's (1859-62) monumental Bonner Durchmusterung (BD). Schoenfeld's survey was carried out using the same methods as had been used for the BD. The procedure consisted of allowing the telescope to drift along the mean declination of each zone and recording the positions and magnitudes of stars crossing the transit... Topics: ASCENT TRAJECTORIES, FLIGHT PATHS, PERFORMANCE PREDICTION, SPACECRAFT TRAJECTORIES, USER MANUALS...
byAnderson, R. R.; Hartung, J. B.; Roddy, D. J.; Shoemaker, E. M
The Manson impact structure (MIS) has a diameter of 35 km and is the largest confirmed impact structure in the United States. The MIS has yielded a Ar-40/Ar-39 age of 65.7 Ma on microcline from its central peak, an age that is indistinguishable from the age of the Cretaceous-Tertiary boundary. In the summer of 1991 the Iowa Geological Survey Bureau and U.S. Geological Survey initiated a research core drilling project on the MIS. The first core was beneath 55 m of glacial drift. The core... Topics: APOLLO FLIGHTS, FLIGHT PATHS, FREE FLIGHT, PROPELLANTS, TERMINAL BALLISTICS, TRAJECTORIES, APOLLO...
Programs in use today generally have all of the functional and information processing capabilities required to do their specified job. However, older programs usually use obsolete technology, are not integrated properly with other programs, and are difficult to maintain. Reengineering is becoming a prominent discipline as organizations try to move their systems to more modern and maintainable technologies. Johnson Space Center's (JSC) Software Technology Branch (STB) is researching and... Topics: EXPEDITIONS, LUNAR MINING, ORBIT TRANSFER VEHICLES, OXYGEN PRODUCTION, ROBOTICS, SPACECRAFT...
This article is the transcription of a lecture entitled 'Research associated with the LaRC 8-Foot Tunnels Branch' by Dr. Richard T. Whitcomb, National Aeronautics and Space Administration, LaRC, Hampton, Va. The lecture was presented at the ARC, 21 Oct. 1970. The lecture ranges over the following topics: supercritical airfoils; flight demonstrations of the F-111, T-2C, and the F-8; an advanced technology transport; swept wing stability; wind tunnel tests; and data acquisition over the Mach... Topics: EXPEDITIONS, LUNAR MINING, ORBIT TRANSFER VEHICLES, OXYGEN PRODUCTION, ROBOTICS, SPACECRAFT...
byExum, Daniel B.; Ilias, S.; Avva, V. S.; Sadler, Bo
The techniques necessary for the fabrication of a complex three-dimensional tubular form using a PMR-type resin have been developed to allow for the construction of several tubes with good physical and mechanical properties. Employing established resin transfer molding practices, the relatively non-hazardous AMB-21 in acetone formulation was used to successfully impregnate four layers of AS4 braided graphite fiber preform previously loaded around an aluminum cylindrical core in an enclosed mold... Topics: REUSABLE LAUNCH VEHICLES, COSTS, REENTRY TRAJECTORIES, DESCENT TRAJECTORIES, EQUATIONS OF MOTION,...
Concurrent tests were performed on a 1/16 and a 1/20 scale model (wing spans of 2.64 and 2.11 ft. respectively) of a modern low wing monoplane in the NACA 15 foot free-spinning wind tunnel. Results are presented in the form of charts that afford a direct comparison between the spins of the two models for a number of different conditions. Qualitatively, the same characteristic effects of control disposition, mass distribution, and dimensional modifications were indicated by both models.... Topics: ATTITUDE CONTROL, STEERING, TABLES (DATA), INDEPENDENT VARIABLES, MULTISTAGE ROCKET VEHICLES,...
byKonradi, G. G.; Kozelkin, V. V.; Novitskiy, L. A.; Shvarev, V. V
Development of space engineering products for use in aerospace environments and their usage in industry Topics: FLYBY MISSIONS, SPACE MISSIONS, URANUS (PLANET), INTERPLANETARY TRAJECTORIES, PLANETARY...